#include "Luau/Scope.h"
#include "Luau/ToString.h"
#include "Luau/TypeArena.h"
#include "Luau/Unifier2.h"
#include "Luau/Error.h"
#include "ScopedFlags.h"
#include "doctest.h"
using namespace Luau;
LUAU_FASTFLAG(DebugLuauForceOldSolver)
LUAU_FASTFLAG(LuauTryToOptimizeSetTypeUnification)
struct Unifier2Fixture
{
TypeArena arena;
BuiltinTypes builtinTypes;
Scope scope{builtinTypes.anyTypePack};
InternalErrorReporter iceReporter;
Unifier2 u2{NotNull{&arena}, NotNull{&builtinTypes}, NotNull{&scope}, NotNull{&iceReporter}};
ToStringOptions opts;
ScopedFastFlag sff{FFlag::DebugLuauForceOldSolver, false};
std::pair<TypeId, FreeType*> freshType()
{
FreeType ft{&scope, builtinTypes.neverType, builtinTypes.unknownType};
TypeId ty = arena.addType(ft);
FreeType* ftv = getMutable<FreeType>(ty);
REQUIRE(ftv != nullptr);
return {ty, ftv};
}
std::string toString(TypeId ty)
{
return ::Luau::toString(ty, opts);
}
std::string toString(TypePackId ty)
{
return ::Luau::toString(ty, opts);
}
};
TEST_SUITE_BEGIN("Unifier2");
TEST_CASE_FIXTURE(Unifier2Fixture, "T <: number")
{
auto [left, freeLeft] = freshType();
CHECK(UnifyResult::Ok == u2.unify(left, builtinTypes.numberType));
CHECK("never" == toString(freeLeft->lowerBound));
CHECK("number" == toString(freeLeft->upperBound));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "number <: T")
{
auto [right, freeRight] = freshType();
CHECK(UnifyResult::Ok == u2.unify(builtinTypes.numberType, right));
CHECK("number" == toString(freeRight->lowerBound));
CHECK("unknown" == toString(freeRight->upperBound));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "T <: U")
{
auto [left, freeLeft] = freshType();
auto [right, freeRight] = freshType();
CHECK(UnifyResult::Ok == u2.unify(left, right));
CHECK("t1 where t1 = ('a <: (t1 <: 'b))" == toString(left));
CHECK("t1 where t1 = (('a <: t1) <: 'b)" == toString(right));
CHECK("never" == toString(freeLeft->lowerBound));
CHECK("t1 where t1 = (('a <: t1) <: 'b)" == toString(freeLeft->upperBound));
CHECK("t1 where t1 = ('a <: (t1 <: 'b))" == toString(freeRight->lowerBound));
CHECK("unknown" == toString(freeRight->upperBound));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "(string) -> () <: (X) -> Y...")
{
TypeId stringToUnit = arena.addType(FunctionType{arena.addTypePack({builtinTypes.stringType}), arena.addTypePack({})});
auto [x, xFree] = freshType();
TypePackId y = arena.freshTypePack(&scope);
TypeId xToY = arena.addType(FunctionType{arena.addTypePack({x}), y});
u2.unify(stringToUnit, xToY);
CHECK("string" == toString(xFree->upperBound));
const TypePack* yPack = get<TypePack>(follow(y));
REQUIRE(yPack != nullptr);
CHECK(0 == yPack->head.size());
CHECK(!yPack->tail);
}
TEST_CASE_FIXTURE(Unifier2Fixture, "unify_binds_free_subtype_tail_pack")
{
TypePackId numberPack = arena.addTypePack({builtinTypes.numberType});
TypePackId freeTail = arena.freshTypePack(&scope);
TypeId freeHead = arena.addType(FreeType{&scope, builtinTypes.neverType, builtinTypes.unknownType});
TypePackId freeAndFree = arena.addTypePack({freeHead}, freeTail);
u2.unify(freeAndFree, numberPack);
CHECK("('a <: number)" == toString(freeAndFree));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "unify_binds_free_supertype_tail_pack")
{
TypePackId numberPack = arena.addTypePack({builtinTypes.numberType});
TypePackId freeTail = arena.freshTypePack(&scope);
TypeId freeHead = arena.addType(FreeType{&scope, builtinTypes.neverType, builtinTypes.unknownType});
TypePackId freeAndFree = arena.addTypePack({freeHead}, freeTail);
u2.unify(numberPack, freeAndFree);
CHECK("(number <: 'a)" == toString(freeAndFree));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "unify_free_type_intersection_in_ub_from_union")
{
TypeId freeTy = arena.addType(FreeType{&scope, builtinTypes.neverType, builtinTypes.unknownType});
TypeId subTy = arena.addType(IntersectionType{{freeTy, builtinTypes.truthyType}});
TypeId superTy = arena.addType(UnionType{{builtinTypes.numberType, builtinTypes.nilType}});
u2.unify(subTy, superTy);
CHECK("('a <: never)" == toString(freeTy));
}
TEST_CASE_FIXTURE(Unifier2Fixture, "unify_free_type_lb_from_intersection")
{
TypeId freeTy = arena.addType(FreeType{&scope, builtinTypes.neverType, builtinTypes.unknownType});
TypeId superTy = arena.addType(UnionType{{freeTy, builtinTypes.nilType}});
TypeId subTy =
arena.addType(IntersectionType{{builtinTypes.stringType, arena.addType(NegationType{arena.addType(SingletonType{StringSingleton{"foo"}})})}});
u2.unify(subTy, superTy);
CHECK("(string & ~\"foo\" <: 'a)" == toString(freeTy));
}
TEST_SUITE_END();